FastMask

Native Android app for managing Fastmail masked emails

Features • Screenshots • Installation • Setup • Tech Stack • Architecture • Contributing

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About

FastMask is a native Android application that lets you manage your Fastmail masked email addresses directly from your phone. Masked emails are disposable addresses that forward to your real inbox, helping you protect your privacy and reduce spam.

Features

Feature	Description
View All Masks	Browse your masked emails in a clean, searchable list
Create New	Generate new masked addresses with custom descriptions
Enable/Disable	Toggle masks on or off without deleting them
Edit Details	Update description, domain, and URL associations
Quick Copy	One-tap copy to clipboard
Delete	Remove masks you no longer need
Search & Filter	Find specific masks instantly
Material You	Dynamic theming that adapts to your wallpaper
20 Languages	Full localization with in-app language picker
Settings	Language selection, contact/feedback, and logout

Screenshots

Screenshots coming soon

Installation

Download APK

1. Go to the Releases page
2. Download the latest APK file
3. Enable "Install from unknown sources" if prompted
4. Install the APK

Build from Source

# Clone the repository
git clone https://github.com/pawelorzech/FastMask.git
cd FastMask

# Build debug APK
./gradlew assembleDebug

# Or build release APK
./gradlew assembleRelease

The APK will be generated in app/build/outputs/apk/

Requirements

• Android 8.0 (API 26) or higher
• Fastmail account with API access

Setup

1. Create a Fastmail API Token

1. Log in to Fastmail
2. Navigate to Settings → Privacy & Security → Integrations → API tokens
3. Click New API token
4. Name it (e.g., "FastMask")
5. Select scope: Masked Email (read/write)
6. Copy the generated token

2. Log in to FastMask

1. Open the app
2. Paste your API token
3. Tap "Log in"

Your token is stored securely using Android's EncryptedSharedPreferences.

Tech Stack

Category	Technology
Language	Kotlin 100%
UI Framework	Jetpack Compose
Design System	Material 3 with dynamic theming
DI	Hilt
Networking	Retrofit + OkHttp
Serialization	Kotlinx Serialization
Async	Coroutines + Flow
API Protocol	JMAP (Fastmail's native protocol)

Architecture

The app follows Clean Architecture principles with MVVM pattern:

app/
├── data/                    # Data layer
│   ├── api/                 # JMAP API service & models
│   ├── local/               # Secure token storage
│   └── repository/          # Repository implementations
│
├── domain/                  # Business logic layer
│   ├── model/               # Domain models
│   ├── repository/          # Repository interfaces
│   └── usecase/             # Use cases
│
├── di/                      # Dependency injection modules
│
└── ui/                      # Presentation layer
    ├── auth/                # Login screen
    ├── list/                # Masked email list
    ├── create/              # Create new mask
    ├── detail/              # View/edit mask details
    ├── settings/            # Settings screen
    ├── components/          # Reusable UI components
    ├── navigation/          # Navigation setup
    └── theme/               # Material 3 theming

Privacy & Security

• Local Storage Only: Your API token is stored locally using Android's EncryptedSharedPreferences
• Direct API Communication: The app communicates directly with Fastmail's servers - no intermediary servers
• No Tracking: Zero analytics, telemetry, or data collection
• Open Source: Full source code available for audit

Contributing

Contributions are welcome! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Development Setup

1. Install Android Studio (latest stable)
2. Clone the repository
3. Open the project in Android Studio
4. Sync Gradle and run on an emulator or device

Code Style

• Follow Kotlin coding conventions
• Use meaningful commit messages
• Write tests for new features when applicable

Changelog

v1.3 (January 2026)

• New: Settings screen with language picker, contact button, and logout
• New: Localization support for 20 languages (English, Chinese, Spanish, Hindi, Arabic, Portuguese, Bengali, Russian, Japanese, French, German, Korean, Italian, Turkish, Vietnamese, Polish, Ukrainian, Dutch, Thai, Indonesian)
• New: In-app language override using AppCompatDelegate
• Improved: All UI strings now use centralized string resources
• Fixed: Choppy navigation transitions between Settings and List screens
• Fixed: Language preference now persists correctly across app restarts
• Improved: Navigation animations simplified (slide-only, 220ms with FastOutSlowInEasing)
• Improved: Soft refresh prevents shimmer loading when returning from Settings

v1.2 (January 2026)

• Fixed: Login crash caused by ParameterizedType casting error at runtime
• Improved: TokenStorage now uses lazy initialization for EncryptedSharedPreferences
• Stability: Deferred crypto initialization prevents reflection errors during Hilt injection

v1.1 (January 2026)

• Fixed: ProGuard/R8 minification crash with ParameterizedType casting error
• Improved: Added proper ProGuard rules for Google Tink (security-crypto dependency)
• Stability: Release builds now work correctly with code minification enabled

v1.0 (Initial Release)

• Manage Fastmail masked emails
• Create, edit, enable/disable, and delete masks
• Material 3 dynamic theming
• Secure token storage with EncryptedSharedPreferences

Roadmap

• Add screenshots to README
• Widget for quick mask creation
• Dark/light mode toggle
• Localization support (20 languages)
• Settings screen with language picker

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Fastmail for their excellent email service and JMAP API
• JMAP for the open standard specification
• The Android and Kotlin communities for amazing tools and libraries

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Made with Kotlin and Jetpack Compose

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